/Engine/Source/Runtime/Core/Public/Math/Quat.h
Fast Linear Quaternion Interpolation. Result is NOT normalized.
static [TQuat](API\Runtime\Core\Math\TQuat)< T > FastLerp ( const [TQuat](API\Runtime\Core\Math\TQuat)< T > & A, const [TQuat](API\Runtime\Core\Math\TQuat)< T > & B, const T Alpha )